开发了一种镍催化的方法,用于在有机锌存在下对具有束缚不饱和度的缺电子烯烃进行环化。观察到每个反应组件的结构具有相当大的灵活性。烯酮、亚烷基丙二酸酯、不饱和β-酮酯和硝基烯烃作为缺电子烯烃参与;炔烃、烯酮、1,3-二烯和醛作为系链不饱和键参与;以及各种 sp2 和 sp3 杂化的有机锌,包括那些具有 β-氢的有机锌,作为亲核组分参与其中。底物结构、有机锌结构和配体结构都在决定产物选择性方面发挥了重要作用。具有特殊合成意义的是从普通炔烃制备 E 或 Z 三或四取代烯烃的机会。
Synthesis of Nitrogen Heterocycles by Intramolecular Michael Type of Amination via Reduction of Imines with Di-n-butyliodotin Hydride (n-Bu2SnIH)
摘要:
Novel nitrogen heterocycles were prepared by a one-pot procedure involving the reductive amination of the bifunctional substrates containing an aldehyde and enone groups with di-n-butyliodotin hydride (n-Bu(2)SnlH).
Diastereodivergent Catalysis Using Modularly Designed Organocatalysts: Synthesis of both<i>cis</i>- and<i>trans</i>-Fused Pyrano[2,3-<i>b</i>]pyrans
作者:Huicai Huang、Swapna Konda、John C.-G. Zhao
DOI:10.1002/anie.201510134
日期:2016.2.5
4a,8a‐tetrahydro‐2H,5H‐pyrano[2,3‐b]pyran‐7‐carboxylates have been obtained in high diastereoselectivities and enantioselectivities from the same starting materials using a tandem inverse‐electron‐demand hetero‐Diels–Alder/oxa‐Michael reaction catalyzed by modularly designed organocatalysts (MDOs). Diastereodivergence was achieved in these reactions through the direct control of the stereochemistry
A catalytic amount of In(OAc) 3 smoothly promoted 1,4-reduction of certain α-enones with PhSiH 3 in ethanol at ambient temperature. The intermediary enolates could be used for inter- and intramolecular aldol reactions andintramolecular Michael addition.
Selective 1,4-reduction of unsaturated carbonyl compounds using Co2(CO)8–H2O
作者:Hee-Yoon Lee、Mihyun An
DOI:10.1016/s0040-4039(03)00462-3
日期:2003.3
α,β-Unsaturated ketones and aldehydes were selectively reduced to the corresponding saturatedcarbonyl compounds by Co2(CO)8–H2O system. The current reducing system also offered a chemoselective reduction of less substituted unsaturated carbonylgroups.
An efficient protocol for the in-flow synthesis of enantiomerically enriched functionalized cyclopentane rings has been developed. By exploiting Evans’ oxazolidinones, the stereoselective light-driven cyclization of bisenones in a coil photoreactor affords, after the removal of the chiral auxiliary, an enantiomerically enriched cyclopentane. The cyclization was also successfully realized in a 3D-printed
已经开发了一种有效的对映体富集功能化环戊烷环的流入合成方案。通过利用 Evans 的恶唑烷酮,双烯酮在线圈光反应器中的立体选择性光驱动环化在去除手性助剂后提供了对映体富集的环戊烷。环化也在 3D 打印的介观反应器中成功实现。
Assessing the scope of the tandem Michael/intramolecular aldol reaction mediated by secondary amines, thiols and phosphines
作者:Elinor L Richards、Patrick J Murphy、Francesca Dinon、Silvia Fratucello、Paul M Brown、Thomas Gelbrich、Michael B Hursthouse
DOI:10.1016/s0040-4020(01)00744-x
日期:2001.9
The outcome of a tandem Michael/intramolecular aldol reaction which is mediated by secondary amines, thiols and phosphines has been found to be highly substrate dependent, with the best results being obtained for the formation of 5 and 6-membered rings using thiol or thiolate nucleophiles. Amine and phosphine mediated cyclisations were found to be problematic in several cases but were still effective